Alloy and its application to the manufacture of electrical conductors



Patented Oct. 16, 19 2 8.

UNITED STATES A 1,688,247 PATENT OFFICE.

'WILLOUGHBY STATHAM SMITH, OF NEWTON POPTLEFORD, HENRY JOSEPH GARNETT,

OF SEVENOAKS, AND JOHN ANGEL HOLDEN, OF GIDEA PARK, ENGLAND.

ALLOY AND ITS APPLICATION TO THE UFACTURE OF ELECTRICAL CONDUCTOBS.

No Drawing. Application filed January 6, 1927, Serial No. 159,497, and in Great Britain July 10, 1820.

The subjects of this invention are quaternary alloys of iron, nickel, aluminium and a variable fourth element. As a fourth element, chromium has been found to be particularly advantageous, as suitable alloys of A feature of this invention is that whereas in' nickel-iron-aluminium alloys (in which nickel predominates and where the aluminium exceeds 3%) forgeability is diflicult, 1n

the quaternary alloys herein described this difficulty does not'exist.

. According to this invention a quaternary alloy free from carbon compr1sesr Per cent. Iron 6-1 Aluminium L 1- 5 A fourth element. 1- 5 I Nickel the balance.

Although these alloys are termed quaternary alloys, yet they may contain a small percentage of a deoxidizing metal, such as ,manganese, cadmium or magnesium.

To obtain the highest resistance and the highest initial permeability the percentages can be still more narrowly defined as Per cent. Iron. 8-11 Aluminium 2- 3 A fourth element 2- 3 Nickel the balance, but not less than 84%.

Thus an alloy containing Nickel the balance when forged, drawn to wire and annealed at 900 C. had'the following properties Electrical resistance 67.5 microhms percm. Initial permeability 8000.

I An alloy free from carbon containing Per cent. Iron I 17.0 Aluminium 2.0 Chromium 1.5

Per cent. I

and the balance nickel,-when forged, drawn to fine w1reand annealed at 900 C. gave a permeability-of 8000 in a field of .001 gauss and 11,500 in a field of .1 gauss together with an electrical resistance of 44.4 microhms per When either the aluminium or the fourth element is given a content approaching its maximum content, the magnetic permeability of the alloy in weak fields will be very con siderably reduced, but the fall will not be so great if the iron content approaches the minimum iron content i, e. 6%. Thus an alloy containing Per cent. Iron -1 Aluminium 2.8 Chromium 5 Nickel the balance I 7 forged, drawn to wire and heat treated had an initial permeabilityof 3000 and an electrical resistance of 80 microhms per em These alloys are very sensitive to heat treatment and in those applications where minimum hysteresis is a very important factor, such as for the wires and tapes used in submarine telegraph .cable systems, great care is necessarynot to over anneal the alloys. For fine wire (from 30 to 40 standard wire, gauge) thin stampings (.006 inches to .020 inchesthick) two minutes annealing at 880 C. inan inert. atmosphere, such as nitrogen, followed by rapid cooling, will develop the magnetic permeability and the-hysteresis will bealmost negligible. What we claim is 1. An alloy free from carbon composed of 6 to 17% :iron, 1 to 5% aluminium, 1 to 5% of a fourth metal for increasing the electrical resistance and selected from agroup comprising chromium, molybdenum, tungsten, vanadium, or silicon and the balancenickel. I 2. An alloy free from carbon composed of 6- to 17%iron, 1 to 5% aluminium, 1 to 5% chromium, and the balance nickel.

3. An alloyfree from carbon composed of 6 to 17% iron, 1 to 5% aluminium, 1 to 5% of a fourth metal for increasing the electrical resistance and selected from a group comprising chromium, molybdenum, tungsten, vanadium, or silicon, a small percentageofa deoxidizing metal, and the balance nickel;

4. An alloy free from carbon composed of i 6 to 17% iron, lto 5% aluminium, 1 to 5% chromium, a small percentage of a deoxidizing metal, and the balance nickel.

5; An alloy free from carbon composed of 6 to 17% iron,- 1 to 5% aluminium, 1' to 5% of a fourth element for increasing the electrical resistance and selected from a group comprising chromium, molybdenum, tungsten, vanadium, or silicon, a small percentage of manganese, and the balance nickel.

6. An alloy freefi'om carbon, composed of 6 to 17% iron, 1 to 5% aluminium, 1 to 5% chromium, a small percentage of manganese, and the balance nickel.

7. An alloy free from carbon composed of 6 to 17 iron, 1 to 5% aluminium,1 to 5% of a metal in Class VI of the periodic system, and the balance nickel.

8. An alloy free from carbon composed of 6 to 17 iron, 1 to 5% aluminium and 1 to 5% of a metal in Class VI of the periodic system, a small percentage of a deo'xidizing metal, and the balance nickel.

9. An alloy free from carbon composed of iron 8 to 11%, aluminium 2 to 3% and a fourth metal 2120 3%, said metal increasing the electrical resistance and being selected from a group comprising chromium, molybdenum, tungsten, vanadium, or silicon, and. 'the balance nickel, but, however, not less,

than 84%.

10. An alloyfree from carbon composed of iron 8 to 11%, aluminium 2 to 3%and a fourth metal 2 to 3%, said metal increasing the electricalresistance and being selected from a group comprising chromium, molyb-' denum, tungsten, vanadium, or *silicon, a

small percentage of adeoxidizing metal, and

the balance nickel,-not,,.however, less than 3%, and the balance nickel, not, however, less than 84%.

In testimony that we claim the foregoing as our invention, we have signed our names this 21st day of December, 1926.

WILLOUGHBY sTATH AM SMITH. HENRY JOSEPH GARNETT. JOHN ANGEL HOLDEN. 

